what's the trick to making this jump - I've been at it for a long time and it seems pretty impossible. I'm starting before the smaller ramp prior to this big jump and I can make the turn without bumping but it still isn't fast enough.

After each level, we loose some of our weapons, therefore I don't have the pistol and laser sight, so how do I disable the sentry gun that is next to the bike. I've done the rolling balls, got the torch, lit three fires, killed the guard and have gone into the room behind the sentry gun with the window/gap behind it. I have tried using the pistols while jumping up and down no luck. I've tried using the shot gun . What is the trick to doing this